Nitric oxide is an important inter and intra-cellular messenger which has been implicated in the pathogenesis of septic shock. Inhibition of nitric oxide synthase is under investigation as a treatment for hypotension in septic shock. In addition to the vasodilating effect of nitric oxide on vascular smooth muscle, nitric oxide also has effects on platelets and immune cells. In this investigation, we are examining the role of the nitric oxide pathway as a modulator of immune cell function.